There has been known a technique relating to a remote conference. For example, a known communication device is installed at each location for a television conference in a television conference system. In the television conference system, each communication device is connected to the other communication devices to perform a television conference. Each communication device includes a monitor, on which a plurality of windows is displayed. Upon receipt of moving image data from one or more other communication devices installed at other respective locations, a communication device displays moving images of the respective locations in respective windows on the monitor. In the communication device, for example, when a size of a window in which a moving image is displayed is reduced, a control command for decreasing a frame rate or resolution of moving image data is generated. For another example, when a window is dismissed, a control command for stopping transmission of moving image data is generated. Such a control command is transmitted to a communication device that sent the moving image data.